EP0481487A2 - Bereitschaftsbetriebsteuerschaltung - Google Patents

Bereitschaftsbetriebsteuerschaltung Download PDF

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Publication number
EP0481487A2
EP0481487A2 EP91117750A EP91117750A EP0481487A2 EP 0481487 A2 EP0481487 A2 EP 0481487A2 EP 91117750 A EP91117750 A EP 91117750A EP 91117750 A EP91117750 A EP 91117750A EP 0481487 A2 EP0481487 A2 EP 0481487A2
Authority
EP
European Patent Office
Prior art keywords
stand
mosfet
control circuit
gate
signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP91117750A
Other languages
English (en)
French (fr)
Other versions
EP0481487A3 (en
Inventor
Hiroshi C/O Nec Corporation Katsuta
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Publication of EP0481487A2 publication Critical patent/EP0481487A2/de
Publication of EP0481487A3 publication Critical patent/EP0481487A3/xx
Withdrawn legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/28—Testing of electronic circuits, e.g. by signal tracer
    • G01R31/30—Marginal testing, e.g. by varying supply voltage
    • G01R31/3004—Current or voltage test
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
    • G06F1/26—Power supply means, e.g. regulation thereof
    • G06F1/32—Means for saving power

Definitions

  • This invention relates to a stand-by control circuit, and more particularly to, a stand-by control circuit for controlling a low power consumption operation mode called as a stand-by mode of a microcomputer.
  • microcomputers have been applied to machines such as office automation machines.
  • Microcomputers used in such machines are required to have a performance of low power consumption, because the machines are applied with a power supply from batteries equipped in the machines in accordance with tendencies of small size and light weight thereof.
  • microcomputers are programmed to operate with low power consumption mode called as "stand-by mode".
  • stand-by mode the microcomputer halts its processing operation with maintaining information of internal states of the microcomputer in registers, flags, RAMs, etc.
  • the microcomputer goes into the stand-by mode by carrying out a stand-by control command, and is released from the stand-by mode by receiving a system reset signal.
  • a conventional stand-by control circuit for controlling stand-by mode operation of a microcomputer includes a stand-by flag of a set/reset type flip-flop, a power ON detecting circuit which supplies a power ON detecting signal to a reset input terminal of the stand-by flag, an AND gate which has two input terminals supplied with a writing signal and a signal of a bus line, and a bus driver which is supplied with an output signal of the stand-by flag and controlled by a reading signal to supply a stand-by signal to the bus line.
  • the power ON detecting circuit usually includes a transistor which is maintained to be at ON state.
  • the power ON detecting circuit detects the power ON state and the power ON detecting signal becomes active to be supplied to the stand-by flag to reset.
  • the stand-by flag is set when the AND gate supplies a set signal of logic level "1" on condition that the writing signal is active and the bus line is high level.
  • An output signal of the stand-by flag is supplied to the bus line through the bus driver when a reading signal supplied to the bus driver becomes active.
  • the power ON detecting signal supplied from the power ON detecting circuit becomes active, just after the power supply is turned on and remains active until the power supply voltage becomes as high as the inversion level, then the power ON detecting signal becomes inactive. In such operation, a constant current flows through the transistor which is maintained at ON state in the power ON detecting circuit.
  • the stand-by flag is controlled to be at a set state, when a system is reset after the release of the stand-by mode, while the stand-by flag is controlled to be at a reset state, when the system is reset by turning a power supply on, so that the two reset states of the system are easily distinguished.
  • a stand-by control circuit comprises; means for detecting a state of a power supply; a flag which is reset by a power ON detecting signal supplied from the detecting means; wherein the detecting means comprises means for shutting off a current flowing through the detecting means during a testing mode carried out in accordance with a testing signal.
  • the conventional stand-by control circuit includes a stand-by flag 31 of a set/reset type flip-flop, a power ON detecting circuit 32 which supplies a power ON detecting signal 33 to a reset input terminal of the stand-by flag 31, an AND gate 34 which has two input terminals supplied with a stand-by flag writing signal (SBFW) 35 and a signal of a bus line 38, and a bus driver 36 which is supplied with an output signal of the stand-by flag 31 and controlled by a stand-by flag reading signal (SBFR) 37 to supply a stand-by signal to the bus line 38.
  • the power ON detecting circuit 32 usually includes a transistor which is maintained to be at ON state.
  • the power ON detecting circuit 32 detects the power ON state to supply a power ON detecting signal to the stand-by flag 31 which is thereby reset.
  • the stand-by flag 31 is set when the AND gate 34 supplies a set signal of logic level "1" on condition that the writing signal 35 is active and the bus line 38 is high level.
  • An output signal of the stand-by flag 31 is supplied to the bus line 38 through the bus driver 36 when a reading signal 37 supplied to the bus driver 36 becomes active.
  • the power ON detecting signal 33 supplied from the power ON detecting circuit 32 becomes active in accordance with the change of a logic threshold voltage at the time of turning the power supply ON, just after the power supply is turned on, and the power ON detecting signal 33 becomes inactive, when the power supply voltage becomes as high as the inversion level.
  • a constant current flows through the transistor of the constantly ON state in the power ON detecting circuit 32.
  • the stand-by control circuit includes a stand-by flag 1 of a set/reset type flip-flop, a P-MOSFET 2, AN N-MOSFET 3, A NOR gate 5, an AND gate 8, and a bus driver 10.
  • the P-MOSFET 2 is connected at a gate to a testing signal line 7, at a source to a power supply level, and at a nodal point B.
  • the N-MOSFET 3 is connected at a gate to the power supply level, at a source to ground, and at a drain to the nodal point B.
  • the NOR gate 5 is connected at two input terminals to the testing signal line 7 and the nodal point B, and at an output terminal to a reset terminal of the stand-by flag 1.
  • the AND gate 8 is connected at two input terminals to a writing signal line 9 and a nodal point A.
  • the stand-by flag 1 is connected at an output terminal to an input terminal of the bus driver 10.
  • the bus driver 10 is connected at a control terminal to a reading signal line 11 and at an output terminal to the nodal point A.
  • the testing signal is inactive, so that the P-MOSFET 2 is at ON state.
  • the power supply is turned on (time t1 ), so that the power supply voltage increases gradually, as shown in Fig. 3, and the N-MOSFET 3 is turned on.
  • the power ON detecting signal level which is a voltage level of the nodal point B is maintained to be low level until the power supply voltage becomes the inversion level. Therefore, the NOR gate 5 is supplied with two low level input signals, so that the NOR gate 5 supplies a high level signal to the reset terminal of the stand-by flag 1 to be reset.
  • the power ON detecting signal becomes high level (time t2 ), so that the NOR gate 5 supplies a low level signal to the stand-by flag 1.
  • the stand-by flag 1 is set when the AND gate 8 supplies a set signal of logic level "1" on condition that the stand-by flag writing signal (SBFW) 9 is active and the bus line 12 is at a high level.
  • An output signal of the stand-by flag 1 is supplied to the bus line 12 through the bus driver 10 when a stand-by flag reading signal (SBFR) 11 supplied to the bus driver 10 becomes active.
  • SBFR stand-by flag reading signal
  • the testing signal is set to be high (time t 3 ), so that the P-MOSFET 2 becomes at OFF state. Therefore, no current flows through the P-MOSFET 2 and the N-MOSFET 3, and the power ON detecting signal becomes low level.
  • the NOR gate 5 is supplies with a high level, so that it supplies the reset terminal of the stand-by flag with a low level signal. After the time t2 , no constant current flows through the P- and N-MOSFETs 2 and 3.
  • the testing signal may be supplied from an external terminal of the microcomputer, or may be supplied form a testing mode changing circuit provided in the microcomputer.
  • Fig. 4 shows a microcomputer 40 including the stand-by control circuit in the first preferred embodiment.
  • a stand-by flag control circuit 42 which is included in the stand-by control circuit 43 is supplied with a testing signal 45 through an external terminal 44 of the microcomputer 40.
  • a CPU 41 of the microcomputer 40 and the stand-by control circuit 43 are connected each other by a bus line 49. The CPU 41 is also supplied with the testing signal 45.
  • the microcomputer 40 has a testing mode as well as an ordinary operation mode for operating command processes. Switching of the two modes are determined by the testing signal 45 which is determined by an input logic level of the external terminal 44.
  • the ordinary operation mode is selected when the input logic level thereof is "0", and the testing mode is selected when the input logic level thereof is "1".
  • the testing signal 45 is supplied directly from the external terminal 44, however, the testing signal 45 may be supplied from a register for storing a data determining a testing mode in the microcomputer 40.
  • the stand-by control circuit includes a stand-by flag 13 of a set/reset type flip-flop, a P-MOSFET 14, two N-MOSFETs 15 and 19, two inverters 17 and 20, an AND gate 22, and a bus driver 24.
  • the P-MOSFET 14 is connected at a gate to ground, at a source to a power supply level, and at a drain to a nodal point D.
  • the N-MOSFET 19 is connected at a gate to the testing signal line 21 through the inverter 20, at a source to a drain of the N-MOSFET 15, and at a drain to the nodal point D.
  • the N-MOSFET 15 is connected at a gate to the power supply level, at a source to ground.
  • the stand-by flag 13 is connected at a reset terminal to the nodal point D through the inverter 17, at a set terminal to an output of the AND gate 22, and at an output terminal to a nodal point C through the bus driver 24.
  • the AND gate 22 is connected at two input terminals to a writing signal line 23 and a nodal point C.
  • the bus driver 24 is connected at a control terminal to a reading signal line 25.
  • the testing signal is set to be inactive, so that the N-MOSFET 19 is applied at the gate with a high level to be at ON state.
  • the power supply voltage increases gradually, as shown in Fig. 6, and the N-MOSFET 15 becomes ON state.
  • the P-MOSFET 14 is constantly at ON state.
  • the power ON detecting signal level which is a voltage level of the nodal point D is maintained to be low level until the power supply voltage becomes the inversion level (time t2 ).
  • the stand-by flag 13 is supplied at the reset terminal with a high level signal through the inverter 17 to be reset.
  • the power detecting signal becomes high level, so that the stand-by flag 13 is supplied at the reset terminal with a low level.
  • the stand-by flag 13 is set when the AND gate 22 supplies a set signal of logic level "1" on condition that the writing signal (SPFW) 23 is active and the bus line 26 is high level.
  • An output signal of the stand-by flag 13 is supplied to the bus line 26 through the bus driver 24 when a reading signal (SPFR) 25 supplied to the bus driver 24 becomes active.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Microcomputers (AREA)
  • Electronic Switches (AREA)
EP19910117750 1990-10-17 1991-10-17 Stand-by control circuit Withdrawn EP0481487A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP278268/90 1990-10-17
JP27826890 1990-10-17

Publications (2)

Publication Number Publication Date
EP0481487A2 true EP0481487A2 (de) 1992-04-22
EP0481487A3 EP0481487A3 (en) 1994-10-26

Family

ID=17594978

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910117750 Withdrawn EP0481487A3 (en) 1990-10-17 1991-10-17 Stand-by control circuit

Country Status (2)

Country Link
US (1) US5349586A (de)
EP (1) EP0481487A3 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997036232A1 (de) * 1996-03-23 1997-10-02 Robert Bosch Gmbh System zum test eines in einem steuergerät eingebauten rechners

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5450417A (en) * 1993-10-26 1995-09-12 Texas Instruments Incorporated Circuit for testing power-on-reset circuitry
US5455799A (en) * 1994-06-29 1995-10-03 Sgs-Thomson Microelectronics, Inc. Circuit which provides power on reset disable during a test mode
JP3434762B2 (ja) * 1999-12-27 2003-08-11 エヌイーシーマイクロシステム株式会社 半導体集積回路
US7185659B2 (en) * 2003-01-31 2007-03-06 Philip Morris Usa Inc. Inductive heating magnetic structure for removing condensates from electrical smoking device
DE112012004756T5 (de) 2011-11-15 2014-10-30 Isaberg Rapid Ab Detektor-Anordnung in einer Stromkreis-Anordnung mit Standby-Abschaltung

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3680061A (en) * 1970-04-30 1972-07-25 Ncr Co Integrated circuit bipolar random access memory system with low stand-by power consumption
US4120047A (en) * 1977-04-20 1978-10-10 National Semiconductor Corporation Quasi-static MOS memory array with standby operation
JPS6023432B2 (ja) * 1977-12-09 1985-06-07 株式会社日立製作所 Ｍｏｓメモリ
JPS58127262A (ja) * 1982-01-25 1983-07-29 Toshiba Corp マイクロコンピユ−タ
JPS58140649A (ja) * 1982-02-16 1983-08-20 Fujitsu Ltd 電圧検出回路
JPH0693616B2 (ja) * 1986-07-21 1994-11-16 沖電気工業株式会社 リセツト回路
JPS6427094A (en) * 1987-07-23 1989-01-30 Mitsubishi Electric Corp Mos-type semiconductor memory
JPH0197016A (ja) * 1987-10-09 1989-04-14 Fujitsu Ltd 半導体集積回路装置
US4999519A (en) * 1987-12-04 1991-03-12 Hitachi Vlsi Engineering Corporation Semiconductor circuit with low power consumption having emitter-coupled logic or differential amplifier
JPH06100947B2 (ja) * 1988-01-29 1994-12-12 日本電気株式会社 電源制御回路
JPH0389182A (ja) * 1989-08-31 1991-04-15 Sharp Corp 集積回路装置
JPH07109864B2 (ja) * 1989-09-13 1995-11-22 シャープ株式会社 スタティックｒａｍ
JP3061836B2 (ja) * 1990-05-22 2000-07-10 日本電気株式会社 メモリ装置
JP2591305B2 (ja) * 1990-09-30 1997-03-19 日本電気株式会社 パワーオンリセット回路

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997036232A1 (de) * 1996-03-23 1997-10-02 Robert Bosch Gmbh System zum test eines in einem steuergerät eingebauten rechners
US6035421A (en) * 1996-03-23 2000-03-07 Robert Bosch Gmbh System for testing a computer built into a control device

Also Published As

Publication number Publication date
US5349586A (en) 1994-09-20
EP0481487A3 (en) 1994-10-26

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